PVA, Starch/PVA, and Starch/PVA/sugar samples of different
concentrations (10, 20, 30 and 40 % wt/wt) were prepared by casting
method. DSC analysis was carried; the results showed only one glass
transition temperature (Tg) for the samples involved, which suggest
that starch/PVA and starch/PVA/sugar blends are miscible. The
miscibility is attributed to the hydrogen bonds between PVA and
starch. This is in a good agreement with (FTIR) results. Tg and Tm
decrease with starch and sugar content compared with that for
(PVA). Systematic decrease in ultimate strength, due to starch and
sugar ratio increase, is attributed to (PVA), which has more hydroxyl
groups that made its ultimate strength higher than that for
starch/PVA, and starch/PVA/sugar blends. It is observed from water
uptake tests that the solubility time decreases with starch ratio; it is
attributed to decrease in hydroxyl groups caused by PVA ratio
decrease. The inter- and inter-molecular bonds of the hydroxyl
groups enhanced the solubility process of the starch/PVA blends in
water. The water immersion causes hydrogen bonds (inter and
intermolecular bonds) to decompose, that increases the film
solubility. Water absorption and capacity of degradability are most
important in biodegradable materials. The results suggest the samples
that have undergone investigation, can be used for shopping, and
food packaging.
The study of soil burial for the sample at (3cm) depth, and at (13cm)
depth has exhibited weight loss increase with soil burial time. The
biodegradability rapidly increases at the first (6-7) weeks; it is found
that the weight loss at (3cm) depth is greater than that at (13cm) that
was attributed to the differences in the availability of oxygen ratio. It
is found that PVA undergoes lowest weight loss, the weight loss
changes with starch, and sugar content. In dry soil, the weight loss is
lower. The results proved that the biodegradation decreases with soil
burial time after seven weeks of burial. It is concluded that the
samples involved are biodegradable material that can be used for
packaging applications and biologically friendly synthetic polymer
blends to solve the solid waste accumulation problem.
The electrical characteristics of polyvinyl alcohol PVA doped with different concentrations (0, 1, 2, 3 and 4wt%) of sodium iodide NaI powder were studied. The films are prepared using solution casting technique, in order to investigate the effect of sodium iodide NaI additions on the electrical properties of PVA host. The D.C conductivity measured by measuring the D.C electrical resistance using the Keithly Electrometer type 616C, and for different temperatures ranging from 30 – 70oC.
The dielectric properties measured by measuring the capacitor and the loss
... Show MoreThe polymeric hydrogels composed of poly vinyl alcohol (m.wt 72000) and glutaraldehyde(5%,8% and 10%) , have been thermally prepared for the purpose of studying their swelling and drug release behavior . The swelling ratio was measured for all the hydrogel samples at 37°C, in three different media pH (1.2, 4.7 and 6.8) as a function of time. The results show that the maximum swelling ratios were arranged as follows :pH =6.8 > pH =4.7 > pH =1.2 hydrogels cross linked PVA showed a typical pH responsive behavior such as high pH has maximum swelling while low pH shows minimum swelling.
Distribution of light intensity in the flat photobioreactor for microalgae cultivation as a step design for production of bio-renewable energy was addressed in the current study. Five sizes of bioreactors with specific distances from the main light source were adopted as independent variables in experiential design model. The results showed that the bioreactor’s location according to the light source, determines the nature of light intensity distribution in the reactor body. However, the cross-section area plays an important role in determining the suitable location of reactor to achieve required light homogeneity. This area could change even the expected response of the light passing through the reactor if Beer-Lambert's law is adopted.
... Show MoreTheoretical calculations are achieved to study the effect of different deuterium pressures on various characteristics parameters for PF400J plasma focus using an international computer code. Axial and radial velocities, voltage tube, plasma temperatures, and neutron yields at different operating deuterium pressures are computed. Neutron emission has been calculated in the device. The maximum total neutron yield calculated is of the order of and neutrons per shot for entire pressure used. The computed results agree reasonably well with the published neutron yield curves.
In our work present, the application of strong-Lensing observations for some gravitational lenses have been adopted to study the geometry of the universe and to explain the physics and the size of the quasars. The first procedure was to study the geometrical of the Lensing system to determine the relation between the redshift of the gravitational observations with its distances. The second procedure was to compare between the angular diameter distances "DA" calculated from the Euclidean case with that from the Freedman models, then evaluating the diameter of the system lens. The results concluded that the phenomena are restricted to the ratio of distance between lens and source with the diameter of the lens noticing.
The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm2 current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for et
... Show MoreThe purpose of this paper is to apply different transportation models in their minimum and maximum values by finding starting basic feasible solution and finding the optimal solution. The requirements of transportation models were presented with one of their applications in the case of minimizing the objective function, which was conducted by the researcher as real data, which took place one month in 2015, in one of the poultry farms for the production of eggs
... Show MoreMolecularly imprinted polymers (MIPs) are an effective method for separating enantiomeric compounds. The main objective of this research is to synthesize D-arabinitol MIPs, which can selectively separate D-arabinitol and its potential application to differentiate it from its enantiomer compound through a non-covalent approach. A macroporous polymer was synthesized using D-arabinitol as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylate (EGDMA) being a cross-linker, dimethylsulfoxide (DMSO) being a porogen, as well as benzoyl peroxide being an initiator. After polymer synthesis, D-arabinitol was removed by a mixture of methanol and acetic acid (4:1, v/v). Fourier-Transform Infrared spectroscopy (FT-IR) and Scan
... Show MoreIn this paper, we have generalized the concept of one dimensional Emad - Falih integral transform into two dimensional, namely, a double Emad - Falih integral transform. Further, some main properties and theorems related to the double Emad - Falih transform are established. To show the proposed transform's efficiency, high accuracy, and applicability, we have implemented the new integral transform for solving partial differential equations. Many researchers have used double integral transformations in solving partial differential equations and their applications. One of the most important uses of double integral transformations is how to solve partial differential equations and turning them into simple algebraic ones. The most important
... Show MoreThis study suggests using the recycled plastic waste to prepare the polymer matrix composite (PMCs) to use in different applications. Composite materials were prepared by mixing the polyester resin (UP) with plastic waste, two types of plastic waste were used in this work included polyethylene-terephthalate (PET) and Polyvinyl chloride (PVC) with varies weight fractions (0, 5, 10, 15, 20 and 25 %) added as a filler in flakes form. Charpy impact test was performed on the prepared samples to calculate the values of impact strength (I.S). Flexural and hardness tests were carried out to calculate the values of flexural strength and hardness. Acoustic insulation and optical microscope tests were carried out. In general, it is found that UP/PV
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